program belong_or_no;

{$APPTYPE CONSOLE}

uses
  SysUtils;

var
  i, n, xa, ya, S1, Sr, j: integer;
  y, x: array of integer;
  fin: textFile;

begin
  assignFile(fin, 'input.txt');
  reset(fin);
  readln(fin, n);
  setlength(x, (n-(n div 2)));
  setlength(y, (n-(n div 2)));
  j:=0;
  for i:=0 to (2*n)-1 do
  begin
    if ((i mod 2)=0) then
    begin
      read(fin, x[j]);
      j:=j+1;
    end
    else
      read(fin, y[j-1]);
  end;
  writeln;
  readln(fin);
  read(fin, xa);
  read(fin, ya);
  S1:=0;
  for i:=0 to n-2 do
    S1:=S1 +( abs(xa*y[i]-x[i]*ya+x[i]*y[i+1]-x[i+1]*y[i]+x[i+1]*ya-xa*y[i+1]));
  Sr:=abs(x[0]*y[1]-x[1]*y[0]+x[1]*y[2]-x[2]*y[1] + x[n-2]*y[n-1]-x[n-1]*y[n-2]+x[n-1]*y[0]-x[0]*y[n-1]);
  for i:=1 to n-2 do
    Sr:=Sr+abs(x[i]*y[i+1]-x[i+1]*y[i]);
  if (S1> Sr) then
    write('it does not belong')
  else
    write('belong');
  readln;

end.
 